The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 18, 2000
Filed:
Jan. 09, 1998
Applicant:
Inventor:
Noriaki Yamamoto, Kawasaki, JP;
Assignee:
Nikon Corporation, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
G01J / ;
U.S. Cl.
CPC ...
250548 ; 250229 ; 2502 / ; 355 53 ;
Abstract
An illumination optical apparatus includes a light source emitting an illumination light beam, the illumination light beam being directed along a predetermined optical path, a variable optical filter disposed on the predetermined optical path of the illumination light beam for controlling the intensity of the illumination light beam, a transmissivity of the variable optical filter with respect to the illumination light beam being continuously variable, and an optical integrator receiving the illumination light beam that has passed through the variable optical filter to form a plurality of images of the light source.